Patent GB-1236589-A (GB)
Title: Continuous method of producing indefinite lengths of flexible flat electrical conductors
IPC: H05K3/00
Filed: 1968-07-08
Abstract: 1,236,589. Encapsulating electrical conductors. ELECTRO CONNECTIVE SYSTEMS Inc. 8 July, 1968 [7 July, 1967], No. 32460/68. Heading B2E. Indefinite lengths of encapsulated flexible flat multiple electrical conductors are produced by continuously forming the conductors on one surface of a flexible web of dielectric material continuously passing the web carrying the conductors to a first coating station and a second coating station, applying coatings of liquid dielectric material to successive selected portions of the surface of the web carrying conductors at the first station and at the second station, the coating at one of the stations completely encapsulating an indefinite length of the multiple electrical conductors and the coating of the other station partially encapsulating a portion of the length of the conductors to leave uncoated predetermined portions of the conductors so as to facilitate electrical connection to the conductors, the terminal transverse edges of the coatings at the two stations being aligned. As shown in Fig. 1 web 15 having a top metal foil layer and a bottom electrical insulation layer is fed from roll 18 to the resist station 19 and its drying station 14 where the desired conductor pattern 20 as shown in Fig. 3 is applied. A control band pattern is applied to the edge of the web at this station in the form of an interrupted longitudinal control band 21 with open segments 22. The web then passes through processing stations such as the etching station 23 and then on to the two coating stations 24 and 25 where the roller A of the first station 24 completely coats and encapsulates desired longitudinal portions of the web and roller B of the second station 25 coats only a portion of the web. The rollers apply an insulation material in liquid form, such as a resin which is fluidised by heat or mixture with a solvent. The roller B carries two or more replaceable impression plates (Figure 2 not shown) so that a selection can be made of the coating pattern to be applied. A sensing station 30 positioned immediately prior to the first coating station 24 surveys the interrupted longitudinal control band 21 formed during the resist printing and etching steps and through suitable amplifying and control means causes the actuation of rollers A and B in accordance with a predetermined sequence. The lengths of the open segments 22 are such that the transverse adjustment control of the web as it passes through the coating stations is not effected. Registration of the terminal transverse coating edges formed by rollers A and B can be precisely controlled to ensure accurate alignment and fusing for continuity of coating. The transverse alignment of the web through the coating stations can be controlled by conventional web guide mechanisms in response to the control band 21. Where the distance between coating stations is significant, precise coating may be accomplished by a multiple sensing of the control band (Figure 8 not shown). The sensing may be by a photoelectric unit or the interrupted conductivity of the band may be used as a switching element.